Clinical improvement after surgery for degenerative cervical myelopathy; A comparison of Patient-Reported Outcome Measures during 12-month follow-up

Poor postoperative pain control is associated with poor long-term patient-reported outcomes after elective spine surgery: an observational cohort study

BACKGROUND CONTEXT

A significant proportion of patients experience poorly controlled surgical pain and fail to achieve satisfactory clinical improvement after spine surgery. However, a direct association between these variables has not been previously demonstrated.

PURPOSE

To investigate the association between poor postoperative pain control and patient-reported outcomes after spine surgery.

STUDY DESIGN

Ambispective cohort study.

PATIENT SAMPLE

Consecutive adult patients (≥18-years old) undergoing inpatient elective cervical or thoracolumbar spine surgery.

OUTCOME MEASURE

Poor surgical outcome was defined as failure to achieve a minimal clinically important difference (MCID) of 30% improvement on the Oswestry Disability Index or Neck Disability Index at follow-up (3-months, 1-year, and 2-years).

METHODS

Poor pain control was defined as a mean numeric rating scale score of >4 during the first 24-hours after surgery. Multivariable mixed-effects regression was used to investigate the relationship between poor pain control and changes in surgical outcomes while adjusting for known confounders. Secondarily, the Calgary Postoperative Pain After Spine Surgery (CAPPS) Score was investigated for its ability to predict poor surgical outcome.

RESULTS

Of 1294 patients, 47.8%, 37.3%, and 39.8% failed to achieve the MCID at 3-months, 1-year, and 2-years, respectively. The incidence of poor pain control was 56.9%. Multivariable analyses showed poor pain control after spine surgery was independently associated with failure to achieve the MCID (OR 2.35 [95% CI=1.59-3.46], p<.001) after adjusting for age (p=.18), female sex (p=.57), any nicotine products (p=.041), ASA physical status >2 (p<.001), ≥3 motion segment surgery (p=.008), revision surgery (p=.001), follow-up time (p<.001), and thoracolumbar surgery compared to cervical surgery (p=.004). The CAPPS score was also found to be independently predictive of poor surgical outcome.

CONCLUSION

Poor pain control in the first 24-hours after elective spine surgery was an independent risk factor for poor surgical outcome. Perioperative treatment strategies to improve postoperative pain control may lead to improved patient-reported surgical outcomes.

The Effects of Peri-Operative Adverse Events on Clinical and Patient-Reported Outcomes After Surgery for Degenerative Cervical Myelopathy: An Observational Cohort Study from the Canadian Spine Outcomes and Research Network

BACKGROUND AND OBJECTIVES

There is a lack of data examining the effects of perioperative adverse events (AEs) on long-term outcomes for patients undergoing surgery for degenerative cervical myelopathy. We aimed to investigate associations between the occurrence of perioperative AEs and coprimary outcomes: (1) modified Japanese Orthopaedic Association (mJOA) score and (2) Neck Disability Index (NDI) score.

METHODS

We analyzed data from 800 patients prospectively enrolled in the Canadian Spine Outcomes and Research Network multicenter observational study. The Spine AEs Severity system was used to collect intraoperative and postoperative AEs. Patients were assessed at up to 2 years after surgery using the NDI and the mJOA scale. We used a linear mixed-effect regression to assess the influence of AEs on longitudinal outcome measures as well as multivariable logistic regression to assess factors associated with meeting minimal clinically important difference (MCID) thresholds at 1 year.

RESULTS

There were 167 (20.9%) patients with minor AEs and 36 (4.5%) patients with major AEs. The occurrence of major AEs was associated with an average increase in NDI of 6.8 points (95% CI: 1.1-12.4, P = .019) and reduction of 1.5 points for mJOA scores (95% CI: -2.3 to -0.8, P < .001) up to 2 years after surgery. Occurrence of major AEs reduced the odds of patients achieving MCID targets at 1 year after surgery for mJOA (odds ratio 0.23, 95% CI: 0.086-0.53, P = .001) and for NDI (odds ratio 0.34, 95% CI: 0.11-0.84, P = .032).

CONCLUSION

Major AEs were associated with reduced functional gains and worse recovery trajectories for patients undergoing surgery for degenerative cervical myelopathy. Occurrence of major AEs reduced the probability of achieving mJOA and NDI MCID thresholds at 1 year. Both minor and major AEs significantly increased health resource utilization by reducing the proportion of discharges home and increasing length of stay.

Correction: Clinical improvement after surgery for degenerative cervical myelopathy; A comparison of Patient-Reported Outcome Measures during 12-month follow-up

[This corrects the article DOI: 10.1371/journal.pone.0264954.].

Long-Term Results After Surgery for Degenerative Cervical Myelopathy

BACKGROUND AND OBJECTIVES

Degenerative cervical myelopathy (DCM) is a frequent cause of spinal cord dysfunction, and surgical treatment is considered safe and effective. Long-term results after surgery are limited. This study investigated long-term clinical outcomes through data from the Norwegian registry for spine surgery.

METHODS

Patients operated at the university hospitals serving Central and Northern Norway were approached for long-term follow-up after 3 to 8 years. The primary outcome was change in the Neck Disability Index, and the secondary outcomes were changes in the European Myelopathy Scale score, quality of life (EuroQoL EQ-5D); numeric rating scales (NRS) for headache, neck pain, and arm pain; and perceived benefit of surgery assessed by the Global Perceived Effect scale from 1 year to long-term follow-up.

RESULTS

We included 144 patients operated between January 2013 and June 2018. In total, 123 participants (85.4%) provided patient-reported outcome measures (PROMs) at long-term follow-up. There was no significant change in PROMs from 1 year to long-term follow-up, including Neck Disability Index (mean 1.0, 95% CI -2.1-4.1, P = .53), European Myelopathy Scale score (mean -0.3, 95% CI -0.7-0.1, P = .09), EQ-5D index score (mean -0.02, 95% CI -0.09-0.05, P = .51), NRS neck pain (mean 0.3 95% CI -0.2-0.9, P = .22), NRS arm pain (mean -0.1, 95% CI -0.8-0.5, P = .70), and NRS headache (mean 0.4, 95% CI -0.1-0.9, P = .11). According to Global Perceived Effect assessments, 106/121 patients (87.6%) reported to be stable or improved ("complete recovery," "much better," "slightly better," or "unchanged") at long-term follow-up compared with 88.1% at 1 year. Dichotomizing the outcome data based on severity of DCM did not demonstrate significant changes either.

CONCLUSION

Long-term follow-up of patients undergoing surgery for DCM demonstrates persistence of statistically significant and clinically meaningful improvement across a wide range of PROMs.

Comparison of the patient-derived modified Japanese Orthopaedic Association scale and the European myelopathy score

PURPOSE

To compare the patient-derived modified Japanese Orthopaedic Association (P-mJOA) scale with the European myelopathy score (EMS) for the assessment of patients with degenerative cervical myelopathy (DCM).

METHODS

In this register-based cohort study with prospectively collected data, included patients were surgically treated for DCM and had reported both P-mJOA and EMS scores at baseline, 1-year follow-up, and/or 2-year follow-up to the Swedish Spine Register. P-mJOA and EMS scores were defined as severe (P-mJOA 0-11 and EMS 5-8), moderate (P-mJOA 12-14 and EMS 9-12), or mild (P-mJOA 15-18 and EMS 13-18). P-mJOA and EMS mean scores were compared, and agreement was evaluated with Spearman's rank correlation coefficient (ρ), the intraclass correlation coefficient (ICC), and kappa (κ) statistics.

RESULTS

Included patients (n = 714, mean age 63.2 years, 42.2% female) completed 937 pairs of the P-mJOA and the EMS. The mean P-mJOA and EMS scores were 13.9 ± 3.0 and 14.5 ± 2.7, respectively (mean difference -0.61 [95% CI -0.72 to -0.51; p < 0.001]). Spearman's ρ was 0.84 (p < 0.001), and intra-rater agreement measured with ICC was 0.83 (p < 0.001). Agreement of severity level measured with unweighted and weighted κ was fair (κ = 0.22 [p < 0.001]; κ = 0.34 [p < 0.001], respectively). Severity levels were significantly higher using the P-mJOA (p < 0.001).

CONCLUSION

The P-mJOA and the EMS had similar mean scores, and intra-rater agreement was high, whereas severity levels only demonstrated fair agreement. The EMS has a lower sensitivity for detecting severe myelopathy but shows an increasing agreement with the P-mJOA for milder disease severity. A larger interval to define severe myelopathy with the EMS is recommended.

Patient Characteristics Associated With Worsening of Neck Pain-Related Disability After Surgery for Degenerative Cervical Myelopathy: A Nationwide Study of 1508 Patients

BACKGROUND AND OBJECTIVES

Functional status, pain, and quality of life usually improve after surgery for degenerative cervical myelopathy (DCM), but a subset of patients report worsening. The objective was to define cutoff values for worsening on the Neck Disability Index (NDI) and identify prognostic factors associated with worsening of pain-related disability 12 months after DCM surgery.

METHODS

In this prognostic study based on prospectively collected data from the Norwegian Registry for Spine Surgery, the NDI was the primary outcome. Receiver operating characteristics curve analyses were used to obtain cutoff values, using the global perceived effect scale as an external anchor. Univariable and multivariable analyses were performed using mixed logistic regression to evaluate the relationship between potential prognostic factors and the NDI.

RESULTS

Among the 1508 patients undergoing surgery for myelopathy, 1248 (82.7%) were followed for either 3 or 12 months. Of these, 317 (25.4%) were classified to belong to the worsening group according to the mean NDI percentage change cutoff of 3.3. Multivariable analyses showed that smoking (odds ratio [OR] 3.4: 95% CI 1.2-9.5: P < .001), low educational level (OR 2.5: 95% CI 1.0-6.5: P < .001), and American Society of Anesthesiologists grade >II (OR 2.2: 95% CI 0.7-5.6: P = .004) were associated with worsening. Patients with more severe neck pain (OR 0.8: 95% CI 0.7-1.0: P = .003) and arm pain (OR 0.8: 95% CI 0.7-1.0; P = .007) at baseline were less likely to report worsening.

CONCLUSION

We defined a cutoff value of 3.3 for worsening after DCM surgery using the mean NDI percentage change. The independent prognostic factors associated with worsening of pain-related disability were smoking, low educational level, and American Society of Anesthesiologists grade >II. Patients with more severe neck and arm pain at baseline were less likely to report worsening at 12 months.

Impact of C3 laminectomy on cervical sagittal alignment in cervical laminoplasty: a prospective, randomized controlled trial comparing clinical and radiological outcomes between C3 laminectomy with C4-C6 laminoplasty and C3-C6 laminoplasty

BACKGROUND CONTEXT

C3 laminectomy in cervical laminoplasty is a modified laminoplasty technique that can preserve the semispinalis cervicis muscle attached to the C2 spinous process. Several previous studies have shown that this technique can lead to better outcomes of postoperative axial neck pain and C2-C3 range of motion (ROM) than conventional cervical laminoplasty. However, there is still a lack of understanding of total and proportional postoperative cervical sagittal alignment outcomes.

PURPOSE

To assess the effects of C3 laminectomy in cervical laminoplasty on postoperative cervical alignment and clinical outcomes.

DESIGN

A single-center, patient-blinded, randomized controlled trial.

PATIENT SAMPLE

We included consecutive 126 patients diagnosed with cervical spondylotic myelopathy (CSM) or ossification of posterior longitudinal ligament (OPLL) who were scheduled for cervical laminoplasty from March 2017 to January 2020.

OUTCOME MEASURES

The primary outcome measures were C2-C7 Cobb angle (CA) and neck disability index (NDI). Secondary outcomes measures included other clinical outcomes and radiographic parameters including segmental Cobb angle and presence of C2-C3 interlaminar fusion.

METHODS

Patients were randomly allocated to either the C3 laminectomy with C4-C6 laminoplasty group (LN group) or the C3-C6 laminoplasty group (LP group) at a 1:1 ratio. Laminoplasty was performed using a unilateral open-door technique and stabilized with titanium mini plates. A linear mixed model analysis was employed to examine the longitudinal data from postoperative 1-year through 3-year. Additional analysis between three types of cervical sagittal alignment morphology was done.

RESULTS

Among 122 patients who were randomly allocated to one of two groups (LN group, n=61; LP group, n=61), modified intent-to-treat analysis was done for 109 patients (LN group, n=51, LP group, n=58) who had available at least a year of postoperative data. Postoperative C2-C7 CA was not significantly different between the two groups. However, NDI was significantly different between the two groups (12.8±1.0 in the LN group vs 8.6±1.0 in LP group, p=.005), which exceeded the minimum clinically important difference (MCID). The postoperative C2-C3 CA was significantly greater in the LN group (7.1±0.5° in LN group vs 3.2±0.5° in LP group, p<.001) while C4-C7 CA was significantly smaller in the LN group (3.9±0.8° in LN group vs 7.7±0.7° in LP group, p<.001) with greater cSVA in the LN group (31.6±1.4 mm in LN group vs 25.5±1.3 mm in LP group at postoperative 3-year, p=.002). Postoperative Euro-Quality of Life-5 Dimension (EQ-5D), numerical rating scores for neck pain (NRS-N) were significantly better in the LP group than in the LN group (all p<.05) and only EQ-5D surpassed the MCID. The C2-C3 fusion rate was significantly different between the LN group (9.8%) and the LP group (44.8%) (p<.001). The LN group showed a higher prevalence of a specific cervical alignment morphology characterized by a sigmoid shape with proximal lordosis and distal kyphosis (S curve). This S curve demonstrated significantly unfavorable outcomes across multiple outcome variables.

CONCLUSION

The impact of C3 laminectomy in cervical laminoplasty on postoperative kyphosis among patients with CSM or OPLL did not significantly differ from that of C3-C6 laminoplasty. However, C3 laminectomy in cervical laminoplasty might result in an unfavorable clinical outcome with an unbalanced cervical sagittal alignment characterized by a sigmoid shape with proximal lordosis and distal kyphosis.

Clinical Improvements in Myelopathy Result in Improved Patient-Reported Outcomes Following Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine if myelopathy severity predicted the magnitude of improvement in health-related quality of life metrics following anterior cervical discectomy and fusion (ACDF).

SUMMARY OF BACKGROUND DATA

Surgery for myelopathy is primarily performed to halt disease progression. However, it is still controversial if these patients can expect significant health-related quality-of life improvements following ACDF. We explore the relationship between modified Japanese Orthopaedic Association (mJOA) improvements and its effect on other health-related quality-of life metrics.

MATERIALS AND METHODS

Patients undergoing ACDF for myelopathy were grouped based on preoperative mJOA scores into mild (15-17), moderate (12-14), and severe (<12) groups. Patients were subsequently categorized based on if they attained the minimum clinically detectable improvement (MCID) threshold for mJOA. Multivariate linear regression was performed to determine the magnitude of improvement in ∆patient-reported outcome measures.

RESULTS

A total of 374 patients were identified for inclusion. Of those, 169 (45.2%) had mild myelopathy, 125 (33.4%) had moderate, and 80 (21.4%) had severe myelopathy. Only the moderate and severe groups had significant improvements in mJOA following surgery (mild: P =0.073, moderate: P <0.001, severe: P <0.001). There were no significant differences in the magnitude of improvement for any patient-reported outcome measure based on myelopathy severity, except for mJOA (mild: 0.27, moderate: 1.88, severe: 3.91; P <0.001). Patients meeting the MCID for mJOA had better ∆Short-Form 12 Mental Component Score (3.29 vs. -0.21, P =0.007), ∆Short-Form 12 Physical Component Score (6.82 vs. 1.96, P <0.001), ∆Visual Analog Scale Neck (-3.11 vs. -2.17, P =0.001), ∆Visual Analog Scale Arm (-2.92 vs. -1.48, P <0.001), ∆Neck Disability Index (-18.35 vs. -7.86, P <0.001), and ∆mJOA (3.38 vs. -0.56, P <0.001) compared with patients who did not.

CONCLUSIONS

Worse baseline myelopathy severity predicts worse postoperative outcomes. However, baseline myelopathy severity is not predictive of the magnitude of postoperative improvement with the exception of mJOA. Patients who attain MCID improvement in mJOA had greater postoperative improvement for other health-related quality of life metrics.

Return to work after surgery for degenerative cervical myelopathy: a nationwide registry-based observational study

BACKGROUND

Few studies of high quality exist on return to work (RTW) rate after surgery for degenerative cervical myelopathy (DCM). This study aims to examine the RTW rate in patients undergoing surgery for DCM.

METHODS

Nationwide prospectively collected data were obtained from the Norwegian Registry for Spine Surgery and the Norwegian Labour and Welfare Administration. The primary outcome was return to work, defined as being at work at a given time postoperatively without any medical income-compensation benefits. Secondary endpoints included the neck disability index (NDI) and quality of life measured by EuroQol-5D (EQ-5D).

RESULTS

Among 439 patients operated for DCM between 2012 and 2018, 20% of the patients received a medical income-compensation benefit one year before surgery. This number increased steadily towards the operation at which timepoint 100% received benefits. By 12 months after surgery, 65% had returned to work. By 36 months, 75% had returned to work. Patients that returned to work were more likely to be non-smokers and to have a college education. They had less comorbidity, more were without benefit 1-year pre-surgery, and significantly more patients were employed at operation date. Average days of sick leave in the year before surgery were significantly less in the RTW group, and they had a significantly lower baseline NDI and EQ-5D All PROMs reached statistical significance at 12 months, in favor of the group that achieved RTW.

CONCLUSION

At 12 months following surgery, 65% had returned to work. At the end of the 36-month follow-up period, 75% had returned to work, 5% less than the working percentage in the beginning of the follow-up period. This study demonstrates that a large percentage of patients return to work after surgical treatment for DCM.

Improvement rates, adverse events and predictors of clinical outcome following surgery for degenerative cervical myelopathy

PURPOSE

To investigate improvement rates, adverse events and predictors of clinical outcome after laminectomy alone (LAM) or laminectomy with instrumented fusion (LAM + F) for degenerative cervical myelopathy (DCM).

METHODS

This is a post hoc analysis of a previously published DCM cohort. Improvement rates for European myelopathy score (EMS) and Neck Disability Index (NDI) at 2- and 5-year follow-ups and adverse events are presented descriptively for available cases. Predictor endpoints were EMS and NDI scores at follow-ups, surgeon- and patient-reported complications, and reoperation-free interval. For predictors, univariate and multivariable models were fitted to imputed data.

RESULTS

Mean age of patients (LAM n = 412; LAM + F n = 305) was 68 years, and 37.4% were women. LAM + F patients had more severe spondylolisthesis and less severe kyphosis at baseline, more surgeon-reported complications, more patient-reported complications, and more reoperations (p ≤ 0.05). After imputation, the overall EMS improvement rate was 43.8% at 2 years and 36.3% at 5 years. At follow-ups, worse EMS scores were independent predictors of worse EMS outcomes and older age and worse NDI scores were independent predictors of worse NDI outcomes. LAM + F was associated with more surgeon-reported complications (ratio 1.81; 95% CI 1.17-2.80; p = 0.008). More operated levels were associated with more patient-reported complications (ratio 1.12; 95% CI 1.02-1.22; p = 0.012) and a shorter reoperation-free interval (hazard ratio 1.30; 95% CI 1.08-1.58; p = 0.046).

CONCLUSIONS

These findings suggest that surgical intervention at an earlier myelopathy stage might be beneficial and that less invasive procedures are preferable in this patient population.